Tuukka Niinimäki

Tibiotalocalcaneal Arthrodesis with a Compressive Retrograde Intramedullary Nail: A Report of 34 Consecutive Patients

Background: Tibiotalocalcaneal arthrodesis is a treatment modality for severe arthrosis and malalignment of the hind-foot. Complications, such as delayed union and nonunion, are well-known risks of the procedure. Arthrodesis can be done with a plate, screws, an external fixator, or an intramedullary nail. Compression with an intramedullary nail was the focus of this report. Methods: Thirty-four consecutive patients (23 men and 11 women) with an average age range of 57 (range 25-77) years had tibiotalocalcaneal arthrodesis using retrograde intramedullary compression nail fixation. Mean followup was 24 (range 6 to 43) months. One patient died of an unrelated cause, but 30 (91%) of the remaining 33 patients answered the questionnaire. Results: Bony consolidation was achieved in 26 (76%) patients, the mean time to fusion being 16 weeks. Five patients (15%) had complications and seven (20%) had repeat surgery. Of the 30 patients who responded to the questionnaire, three patients (10%) evaluated the overall result subjectively as being of no benefit and 27 (90%) as improved. The visual analog scale (VAS) score for preoperative pain was 66 at rest and 83 when walking, and the mean postoperative scores were 19 and 32, respectively (p<0.001). Conclusions: Tibiotalocalcaneal arthrodesis with a compressive retrograde intramedullary nail is an effective and safe procedure for patients with severe malalignment or arthrosis of the hindfoot. It is essentially a salvage procedure, and most patients benefit from it, but excellent results are rare.

Unicompartmental Knee Arthroplasty Survivorship is Lower Than TKA Survivorship: A 27-year Finnish Registry Study

BackgroundBalancing the relative advantages and disadvantages of unicompartmental knee arthroplasties (UKAs) against those for TKAs can be challenging. Survivorship is one important end point; arthroplasty registers repeatedly report inferior midterm survival rates, but longer-term data are sparse. Comparing survival directly by using arthroplasty register survival reports also may be inadequate because of differences in indications, implant designs, and patient demographics in patients having UKAs and TKAs.Questions/purposesThe aims of this study were to assess the survivorship of UKA in the context of one large, northern European registry, and to compare the rates of survivorship with those of cemented TKAs performed for primary knee osteoarthritis during the same 27-year period.MethodsFrom the Finnish Arthroplasty Register, we obtained the data for 4713 patients undergoing UKAs for primary osteoarthritis (mean age, 63.5 years; minimum followup, 0 years; mean, 6.0 years; range, 0–24 years) who had surgical revision between 1985 and 2011. From this cohort, we calculated the Kaplan-Meier survivorship for revision performed for any reason and compared it with the survivorship of 83,511 patients (mean age, 69.5 years; minimum followup 0 years; mean, 6.4 years; range, 0–27 years) with TKAs treated for primary osteoarthritis during the same period. Data were adjusted for age and sex in a comparative analysis.ResultsKaplan-Meier survivorship of UKAs was 89.4% at 5 years, 80.6% at 10 years, and 69.6% at 15 years; the corresponding rates for TKAs were 96.3%, 93.3%, and 88.7%, respectively. UKAs had inferior long-term survivorship compared with cemented TKAs, even after adjusting for the age and sex of the patients (hazard ratio 2.2, p < 0.001).ConclusionsA UKA offers tempting advantages compared with a TKA; however, the revision frequency for UKAs in widespread use, as measured in a large, national registry, was poorer than that of TKAs. When choosing between a UKA and a TKA, patients should be informed of advantages of both procedures, but they also should be advised about the generally higher revision risk after UKA.Level of EvidenceLevel III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Survivorship of high tibial osteotomy in the treatment of osteoarthritis of the knee: Finnish registry-based study of 3195 knees

Previous studies from single centres or single-surgeon series report good early and mid-term results for high tibial osteotomy (HTO) in the treatment of osteoarthritis of the knee. However, the survivorship of HTO at a national level is unknown. This registry-based study included 3195 high HTOs performed between 1987 and 2008. Kaplan-Meier analysis revealed an overall survivorship of 89% (95% confidence interval (CI) 88 to 90) at five years and 73% (95% CI 72 to 75) at ten years, when conversion to total knee replacement was taken as the endpoint. Females and patients aged > 50 years had worse survivorship than males or patients aged ≤ 50 years (hazard ratio (HR) 1.26 (95% CI 1.11 to 1.43) and HR 1.41 (95% CI 1.23 to 1.64), respectively). The survivorship of HTOs performed between 1998 to 2008 was worse than for those performed between 1987 and 1997.Previous studies from single centres or single-surgeon series report good early and mid-term results for high tibial osteotomy (HTO) in the treatment of osteoarthritis of the knee. However, the survivorship of HTO at a national level is unknown. This registry-based study included 3195 high HTOs performed between 1987 and 2008. Kaplan-Meier analysis revealed an overall survivorship of 89% (95% confidence interval (CI) 88 to 90) at five years and 73% (95% CI 72 to 75) at ten years, when conversion to total knee replacement was taken as the endpoint. Females and patients aged > 50 years had worse survivorship than males or patients aged ≤ 50 years (hazard ratio (HR) 1.26 (95% CI 1.11 to 1.43) and HR 1.41 (95% CI 1.23 to 1.64), respectively). The survivorship of HTOs performed between 1998 to 2008 was worse than for those performed between 1987 and 1997.

Unicompartmental knee arthroplasties implanted for osteoarthritis with partial loss of joint space have high re-operation rates

The indications and contraindications for unicompartmental knee arthroplasty (UKA) are controversial. The aim of the study was to determine the risk factors for re-operation in our practice. A series of 113 medial UKAs with mean follow-up of 63 months were reviewed retrospectively. Pre-operatively all knees had radiographic or arthroscopic evidence of severe cartilage damage. The re-operation rate was not related to age, gender, arthroscopic finding or body mass index. It was related to the joint space on pre-operative standing weight bearing radiographs taken in extension. The re-operation rate was 6 (95% CI 2.1-17, P<0.001) times higher when the thickness of the pre-operative medial joint space was >2 mm rather than ≤2 mm. It was 8 (95% CI 2.8-22.5, P<0.001) times higher when the thickness of the pre-operative medial space was >40% of the thickness of the lateral space. The ratio of pre-operative joint spaces has a greater influence on revision rate than the absolute measurement and is independent of radiographic magnification or the patients normal cartilage thickness. We therefore recommend that, in medial knee osteoarthritis, UKA should only be used if the pre-operative medial joint space on standing radiographs is ≤40% of the lateral joint space, even if severe cartilage damage is seen arthroscopically.

Two-Stage Revision for Prosthetic Joint Infection: Outcome and Role of Reimplantation Microbiology in 107 Cases

Two-stage revision is widely used for the treatment of prosthetic joint infections. However, the duration of antibiotic treatment between stages and role of reimplantation microbiology are controversial. The purpose of this study was to evaluate the outcome and influence of the reimplantation microbiology of two-staged revisions with 6 weeks of antibiotic treatment. We retrospectively reviewed 107 patients treated with two-stage revision between 2001 and 2009. The overall treatment success rate was 94.4%. The reimplantation cultures were positive in 5/97 (5.2%) cases, and only one of them failed. Therefore, we achieved excellent results with a 6-week course of antibiotics between stages in two-stage revision. Positive reimplantation cultures do not seem to be associated with worse outcomes.

The standing fixed flexion view detects narrowing of the joint space better than the standing extended view in patients with moderate osteoarthritis of the knee

Background and purpose It is unclear whether osteoarthritis (OA) of the knee is seen better in standing flexion position radiographs than in the standing extended view. We assessed the value of standing flexion views. Patients and methods We retrospectively evaluated 1,090 radiographs of 545 consecutive knees with non-traumatic knee pain, comparing standing fixed flexion view (FFV) and standing extended view (SEV). OA was classified according to the Kellgren-Lawrence (KL) radiographic grading scale and joint space widths were measured. Results Medial joint space width was lower on average in the FFV, with the greatest difference in KL II knees. Medial full-thickness loss of cartilage was also seen more often in the FFVs of knees with moderate OA (KL II–III) than in the SEVs (6% vs. 19%). Interpretation Using FFV, there is no need to measure the exact knee flexion angle to use fluoroscopy. In earlier studies, the FFV has been found to be reproducible and easy to use in clinical practice. We recommend using flexion views when deciding the appropriate type of intervention in patients with OA. Full-thickness loss of cartilage in particular is better seen in the flexion view, which may be helpful if planning unicompartmental knee arthroplasty.

The classification of osteonecrosis in patients with cancer: validation of a new radiological classification system

AIM To validate a new, non-joint-specific radiological classification system that is suitable regardless of the site of the osteonecrosis (ON) in patients with cancer. MATERIAL AND METHODS Critical deficiencies in the existing ON classification systems were identified and a new, non-joint-specific radiological classification system was developed. Seventy-two magnetic resonance imaging (MRI) images of patients with cancer and ON lesions were graded, and the validation of the new system was performed by assessing inter- and intra-observer reliability. RESULTS Intra-observer reliability of ON grading was good or very good, with kappa values of 0.79-0.86. Interobserver agreement was lower but still good, with kappa values of 0.62-0.77. Ninety-eight percent of all intra- or interobserver differences were within one grade. Interobserver reliability of assessing the location of ON was very good, with kappa values of 0.93-0.98. CONCLUSION All the available radiological ON classification systems are joint specific. This limitation has spurred the development of multiple systems, which has led to the insufficient use of classifications in ON studies among patients with cancer. The introduced radiological classification system overcomes the problem of joint-specificity, was found to be reliable, and can be used to classify all ON lesions regardless of the affected site.

The diagnosis and classification of osteonecrosis in patients with childhood leukemia

Osteonecrosis is a well‐recognized complication in patients with childhood leukemia. Its clinical relevance is highly dependent on the size and location of the lesion. Therefore, the diagnosis, description of the affected site and the classification of the disease, must be precise. We conducted an extensive literature review to assess the quality of studies reporting the incidence of osteonecrosis in patients with childhood leukemia. Of the 31 included studies, one‐third (32% [n = 10]) did not describe the diagnostic method that was used to assess osteonecrosis. In almost two‐third (61% [n = 19]) of the studies, the osteonecrosis classification system was not used. We conclude that the quality of most published studies on the incidence of osteonecrosis in patients with childhood leukemia is relatively poor because many studies did not describe the radiological method used to diagnose osteonecrosis and/or did not use a validated osteonecrosis classification system. To compare the incidence of osteonecrosis, and to assess the severity and clinical consequences of osteonecrosis in patients with childhood leukemia, there is a need for a robust and widely recognized classification system to grade all cases of osteonecrosis despite the site of lesion. Pediatr Blood Cancer 2015;62:198–203.

Impaired WNT signaling and the spine—Heterozygous WNT1 mutation causes severe age-related spinal pathology

BACKGROUND WNT signaling plays a major role in bone and cartilage metabolism. Impaired WNT/β-catenin signaling leads to early-onset osteoporosis, but specific features in bone and other tissues remain inadequately characterized. We have identified two large Finnish families with early-onset osteoporosis due to a heterozygous WNT1 mutation c.652T>G, p.C218G. This study evaluated the impact of impaired WNT/β-catenin signaling on spinal structures. METHODS Altogether 18 WNT1 mutation-positive (age range 11-76years, median 49years) and 14 mutation-negative subjects (10-77years, median 43years) underwent magnetic resonance imaging (MRI) of the spine. The images were reviewed for spinal alignment, vertebral compression fractures, intervertebral disc changes and possible endplate deterioration. The findings were correlated with clinical data. RESULTS Vertebral compression fractures were present in 78% (7/9) of those aged over 50years but were not seen in younger mutation-positive subjects. All those with fractures had several severely compressed vertebrae. Altogether spinal compression fractures were present in 39% of those with a WNT1 mutation. Only 14% (2/14) mutation-negative subjects had one mild compressed vertebra each. The mutation-positive subjects had a higher mean spinal deformity index (4.0±7.3 vs 0.0±0.4) and more often increased thoracic kyphosis (Z-score>+2.0 in 33% vs 0%). Further, they had more often Schmorl nodes (61% vs 36%), already in adolescence, and their intervertebral discs were enlarged. CONCLUSION Compromised WNT signaling introduces severe and progressive changes to the spinal structures. Schmorl nodes are prevalent even at an early age and increased thoracic kyphosis and compression fractures become evident after the age of 50years. Therapies targeting the WNT pathway may be an effective way to prevent spinal pathology not only in those harboring a mutation but also in the general population with similar pathology.

The reasons for knee arthroplasty revisions are incomparable in the different arthroplasty registries

BACKGROUND The arthroplasty registries report the survivorship of knee arthroplasties and the reasons for revisions. The various registries report similar implant survivorships. However, the reasons for the knee revisions have not been compared. The aims of this study were to assess the reasons for knee arthroplasty revisions from the five valid arthroplasty registries and to evaluate whether the reasons for revisions in each registry were similar. METHODS The reported reasons for knee arthroplasty revisions were extracted from the arthroplasty registries of Australia, New Zealand, Norway, Sweden, and the National Joint Registry for England and Wales. The relevant data were identified from each arthroplasty registrys annual reports. RESULTS All the arthroplasty registries collected data for each performed knee arthroplasty revision using a specific form. The information provided by the registries varied. The numbers of different variables for the revisions were wide-ranging (from 8-33). In addition to the different variables, the reported percentages between the registries had an extremely wide variation. CONCLUSION The reasons for knee arthroplasty revisions are categorized differently in various arthroplasty registries, and there is a wide range of percentages presented. The differences in percentages may not be fully explained by the different outcome results in the different countries. The heterogeneity of the registries may guide the recording of the reasons behind the revisions. There is a definite need to standardize the structure of the arthroplasty registries, and to validate the data therein. A larger collaboration between the registries is essential.